Anyone have a magnetic drain plug? Do they really work or is just a gimmic?

I don't have one, but a number of cars come with them from the factory. As long as the drainplug fits the way a stock one does, I don't see the harm in using one. That being said, I wouldn't spend the money on one.

I dont see it an issue with money - you can get them for 10 bucks shipped...I just want to know if they work or not

What is their purpose?

They grab loose metal particles.

They grab loose metal particles.
Logic says it can only help. Better tip is to make sure you warm your engine up to get a good mixture before you change your oil.

I didn't bought the drain plug, I just stick a strong magnet there. Since my garage change oil with vacumn pump from Dip Stick. I can't say the result for engine. I also do this the the diff and the result is much more fesible there. I can't think of any Con effect with just a magnet.

I haven't used it on my E39 540, but I've used one on a previous car and it did catch small metal particles, flakes. So I guess it does what it's supposed to